1. Field of the Invention
The present invention relates generally to automatic transmissions for vehicles and, more particularly, to an overrunning clutch assembly for an automatic transmission in an automotive vehicle.
2. Description of the Related Art
A conventional automatic transmission includes a hydrodynamic torque converter to transfer engine torque from an engine crankshaft to a rotatable input member of the transmission through fluid-flow forces. The automatic transmission also includes frictional units, typically referred to as clutches, which couple the rotatable input member to one or more members of a planetary gearset. Other frictional units, typically referred to as brakes, hold one or more members of the planetary gearset stationary during flow of power. An example of such an automatic transmission is disclosed in U.S. Pat. No. 4,875,391 to Leising et al.
Such transmissions also typically provide for one or more overrunning clutches in order to improve shift quality. Examples of overrunning clutches for automatic transmissions are ratchet type clutches and traction locking clutches such as a roller ramp or sprag clutch. A discussion of such clutches is disclosed in U.S. Pat. No. 5,070,978 to Pires. It may be desired to provide an overrunning clutch in the automatic transmission to improve shift quality but space within the transmission may be limited. As a result, there is a need in the art to provide an overrunning clutch for a plate and disc pack in an automatic transmission.